PCB (printed circuit board) depaneling, also referred to as singulation, is the procedure of removing a lot of smaller, individual PCB Depaneling from a larger multi-PCB panel produced during manufacturing. The depaneling process was created to be able to increase throughput of PCB manufacturing lines as circuit board sizes reduced. At CMS Laser, our depaneling process has the benefit of speed, pin-point accuracy, no tooling cost or wear, no part induced stress, and no cutting oils or other waste.
Demand Driven by Size
As technology will continue to evolve, the gadgets we use become more advanced and frequently reduction in size. This reduced size requires smaller PCBs. With no set standard for PCBs, every board is made for a specific item. Therefore, this process for depaneling separate boards from the multi-image board is exclusive. Production factors including stress, precision and cleanliness are paramount to keeping board defects as low as possible.
PCBs are generally created in large panels containing multiple boards at the same time, but can also be produced as single units if necessary. The depaneling of PCBs process could be fully automatic, manual, or semi-automatic. There are many methods used, including laser PCB depaneling, in the electronics industry. Let’s examine whatever they are:
The punching method is the procedure of singular PCBs being punched out from the panel by using an exclusive fixture. The punching fixture has sharp blades on one part and supports on the other. An alternative die is necessary for every board and dies must frequently get replaced to keep sharpness. Although the production rate is high, the custom-designed fixtures and blades demand a reoccurring cost.
Boards are scored across the cut line on both sides to lessen overall board thickness. PCBs are subsequently broken out from the panel. Either side in the panel are scored to some depth of approximately 30 percent in the board’s thickness. Once boards have been populated, they may be manually broken out from the panel. There is a strain put on the boards that can damage some of the components or crack the solder joints, in particular those close to the edge of the board.
Wheel Cutting/ Pizza Cutter:
The “pizza cutter” technique is a manual alternative to breaking the net after V-scoring to cut the remaining web. Accuracy is crucial, because the V-score and cutter wheels has to be carefully aligned. There is a slight amount of stress aboard which could affect some components.
Laser depaneling can be carried out on boards requiring high tolerances. Depaneling occurs without physical contact, without any mechanical stress, and is also adaptable to cut requirements through a computer controlled process. Laser depaneling is suitable for installation in surface mount technology (SMT) lines or with board unloaders/loaders for standalone operation.
Most Laser PCB Depaneling are routed leaving the individual circuits linked to the panel frame by narrow tabs which can be subsequently broken or snapped to singulate the circuits. Routing can take up significant panel area as a result of wide kerf width of the physical bit.
Laser routing supplies a complete software-controlled process without reliance on any mechanical dies or blades. Laser routing can cut any shape path including curves and sharp corners. The cut kerf width could be less than 20 microns, providing exceptional accuracy.
Laser routing can be carried out using either:
High-power CO2 laser (~10µm wavelength)
The CO2 laser can thermally cut through FR4, glass fibers along with other rigid and flex circuit substrates at comparatively high speed however with noticeable heat effect on the fringe of the cut for many substrates.
Solid-state UV laser (355nm wavelength).
The UV laser, using a considerably smaller focused spot size, ablates the panel material with considerably less heat and a narrower kerf width. However, because of lower power levels, the cutting speed is significantly vboqdt compared to the CO2 laser and the cost/watt of UV lasers is higher compared to CO2
Generally speaking, firms that are sensitive to char and fine debris along the cut line will employ the UV laser while users who clean the circuits after singulation can benefit from the greater speed of the CO2 laser.
Laser systems for depaneling play an integral role in the future of the PCB manufacturing industry. As need for Pneumatic PCB Depaneling continue to parallel technology trends, like wearables and Internet of Things (IoT) devices, the need for systems that increase production line speed and lower costs for manufacturer will also continue to rise.
Within our Applications Development Lab, we assist each client to ascertain the ideal laser and optics configuration to get a manufacturing process.
Within this three-part series on PCB depaneling, upcoming posts will discuss the benefits and challenges of PCB depaneling, together with the evolution of PCB depaneling with laser systems.